1. Field of the Invention
The present invention relates to a cleaning composition, a method for producing a semiconductor device, and a cleaning method.
2. Description of the Related Art
In the production of semiconductor integrated circuits, progress is being made in terms of increases in scale, increases in density, and miniaturization. In the production of integrated circuits, a lithography step in which a positive type or negative type photoresist is used is employed. A resist film provided on a semiconductor substrate by coating is exposed by an exposure plate such as a photomask or the like. The pattern formed by a photochemical change in the resist film becomes a resist pattern having a shape corresponding to the exposure plate by development. In order to improve the etching resistance of the resist pattern, a post-bake or UV curing is carried out, as needed. The obtained resist pattern is used as a mask to carry out etching or ion injection for the semiconductor substrate.
When the resist pattern is used as a mask to etch a metal layer or an insulating layer on the semiconductor substrate by plasma etching, the photoresist or the residues derived from the metal layer or the insulating layer are formed on the semiconductor substrate. In order to remove the residues formed on the substrate by plasma etching, cleaning using a cleaning composition is carried out.
Furthermore, unnecessary resist patterns are removed thereafter from the semiconductor substrate. Examples of the removing method include a wet type method using a stripper solution and a dry type method involving ashing. Examples of the ashing include plasma ashing. In the method using plasma ashing, an electric field is applied onto oxygen plasma and accelerated in the direction of the electric field to ash the resist pattern. In order to remove the residues generated on the substrate by ashing, a cleaning composition is used.
For example, JP 3219020B discloses a cleaning treatment agent for the surface of a semiconductor substrate provided with a metal wiring, mainly including (a) an organic acid selected from the group consisting of an aminocarboxylic acid selected from oxycarboxylic acids except for monocarboxylic acid, dicarboxylic acid, tricarboxylic acid, and gallic acid, aspartic acid, and glutamic acid, and (b) a complexing agent selected from the group consisting of an aminopolycarboxylic acid selected from ethylenediamine tetraacetic acid and trans-1,2-diaminocyclohexane tetraacetic acid, phosphoric acid derivatives, condensed phosphoric acids, diketones, amines, and inorganic ions selected from halide ions, cyanide ions, thiocyanate ions, thiosulfate ions, and ammonium ions.
In addition, JP3850039B discloses a composition for removing chemically targeted residues from the surface of a metal or a dielectric, in which these chemically targeted residues are applied in the previous step, wherein the composition further suspends the chemically targeted effects from these chemically targeted residues and includes an aqueous solution with a pH of about 3.5 to about 7, and contains (a) a monofunctional, difunctional, or trifunctional organic acid; and (b) a buffering amount of hydroxylamine or a hydroxylamine salt.